If you are using conditional directives in your C# code, you know that you can't set a breakpoint on any code within the directives using Visual Studio. Thankfully, you can add a breakpoint programmatically:
#if MYSYMBOL
#if DEBUG
System.Diagnostics.Debugger.Break();
#endif
DoSomethingForMySymbol();
#else
#if DEBUG
System.Diagnostics.Debugger.Break();
#endif
DoSomethingForEverythingElse();
#endif
System.Diagnostics.Debugger.Break() can only be called in Debug mode, so make sure you wrap it in a #if DEBUG check first. Good luck!